Hinge for oven door



July 23, 1957 c; E. cHEssER .1 2,

HINGE FOR OVEN DOOR Filed Jan. 25', 1954 2 Sheets-Sheet 1 L il ,6]: 6..BY Z ,7925% r y 23, 1957 c. E. CHESSER 2,800,128

HINGE FOR OVEN DOOR I Filed Jan. 25, 1954- I 2 Sheets-Sheet 2 UnitedStates Patent HINGE OVEN DOOR Cecil E. Chesser, Hebron, Ohio, assignorto Sears, Roebuck and Co., Chicago, 11]., a corporation of New York IApplication January 25, 1954, Serial No. 405,965 12 Cl'aims. (Cl.126-191) My invention relates to hinges especially applicable to ovendoors and the like, although. useful for cabinets generally havingdownwardly swinging doors.

Among the objects. of my invention are provision of a new and improvedhinge for oven doors and like appliances which. will be especiallysimple in construction, quickly and easily assembled because subject toconvenient sub-assembly, inexpensive to produce, and which will providea fully balanced door in all positions. Thus, a door provided with myinmproved hinge can be opened and closed with a minimum of effort..

3 Another advantage of my invention isthat my improved hinge ispreferably attached directly to the oven liner rather than tothe stoveframe, as is commonly the case; hence, there is no substantialheatdifferential between the hinge and the parts. to which it is' attachedand, therefore, a proper closure is provided by the door at alloventemperatures, avoiding. the difliculties usually encountered where.the door is hinged to the stove frame or other parts cooler than theoven. a

My invention will be best understood by reference to the drawingsforming a part of this specification and illustrating a preferredembodiment of'myi-nvention, where- Fig. 1 is a fragmentary sideelevational view showing my improved hinge attached to a door andassociated stove parts, the door being shown in partially open position;

Fig. 2 is a similar view with the door in fully closed position; i v

Fig. 3 is a similar view with the door fully open, and

Fig.4 is a sectional view taken substantially along the line 44 of Fig.3. r

The numeralindicates generally a stove or other cabinet and'morespecifically a kitchen range, suchas a gas or electric range forcooking, baking, broiling, etc. Such a range as now commonly constructedhas a skeleton frame, usually formed of structural metal, the numera1 12indicating a vertical corner support and 13 being a horizontalstructural member extending from front to rear and disposed at thebottom of an oven. The oven usually has a sheet metal liner 15, an outerpanel of metal, with intermediate insulating material (not shown) beingattached outside of the liner 15.

A door D is mounted at the front portion of the range and my inventionis particularly concerned with the hinging mechanism for mounting thedoor on the range. (Although one hinge only is shown, it will beunderstood that, for best results, as to balance, the hinge constructionwill be duplicated on opposite sides of the door.) Attached to a side ofthe door D, as by means of screws and nuts 18, is an angular bracket 20which may be of more or less Z- formation, as seen best in section inFig. 4. Pivotally attached to the bracket 20 are a pair of arms or links23 and 25. These arms are preferably formed of stiff sheet metal, thearm 25 being of approximately U-formation and fixedly secured to theoven liner by any suitable means such as a screw, etc. as at 27. The arm23 has a substan- 2,800,128 Patented July 23, 1957 ice . 2 tiallystraight portion 24 and an arcuate portion 24. The arm 25 has anextension 28 extending toward the door and adjacent this end, as at 29,itis pivotally secured to a lever 3,1, this. lever being attached to atension-coil spring 33, as at 34.

Spring 33 is in turn attached at its opposite end to the stove frame ata point not seen in the drawings.

Arm 23 is pivotally attached to the bracket 20 as at 35 and at itsopposite end, as indicated at 37, arm 23 is pivotally connected to a camplate 40. I This cam plate has a convex arcuat'e dwell '42 with a slightreverse portion serving as a stop, as hereinafter described.

The lever 31 at one end has a slightly offset extension 45 which carriesa roller bearing 47,, the latter normally engaging the dwell' of the camplate 40 by reason of the tension. of spring 33 acting on lever 31.Another tension spring 48 attached to the support 12 of the stove frameas at 49 is secured to cam plate 40 as at 50, at such a point that thecam. may rotate about 45 degrees before the spring goes into tension, asseen in Figs. 1 and 3. 1 The cam plate 40 is provided with a keyholeslot 53 engageable withalstud 55 which is T-shaped in section, the headof the stud 55 overlying the edges of and being swiveled in the slot 53and this stud 55 being carried by an ear 56 extending from the arm 25.

If desired, auxiliary tensioning meansof orthodox construction, and,therefore,"not shown, maybe attached to the lower portion of the door Dand adjustably secured to the stove frame whereby closing tension on thedoor may be adjusted to compensate for warpage or the like.

It is believed that the operation of the construction just describedwill be clear. The door when closed will. assume a positionsubstantially as shown in Fig. 2, together with tlre hinge andassociated parts. When his desired to open the door, as seen in Fig. l,the gravity pull on the door will becompensated for by the tension ofspring 33 acting through the lever 31 and cam. plate 40,. the latterreacting on the door through link 23. As the door moves farther openbeyond the position shown in Fig; 1, auxiliary' sprin'g 48 goes intoeffect. These forces will continue with increasing effect until the doorhas assumed a fully open position as seen in Fig. 3. Obviously,

in closing the dooragainst. the pull of gravity, the tensional effectofthe aforesaid. springs will work in favor of closing the door and inovercoming the effect of gravity.

I have found that oven doors equipped with my improved hinge operate.extremely smoothly in all positions, the door being, well balanced inall positions, so that it will remain in any angular position in whichit is manually placed.

It should be noted, furthermore, that when the door is closed the roller47 will be disposed in the concave portion 60 of the cam surface wherethe pressure of the roller tends to retain the door in closed position.Thus, the cam plate serves also as a closure stop by reason of V theslight humpthereon.

It should be noted, furthermore, that between the fully closed positionof the door as seen in Fig. 2 and the partially open position as seen inFig. 1 the auxiliary spring 48 exerts no force whatsoever, this springstension coming into play only between the partially open position ofFig. l and the fully open position of Fig. 3, where gravity is mosteffective on the door, Whereas the tension of the main spring 33 is inforce in substantially all positions of the door. This makes forespecially smooth action and proper balance in all positions of thedoor.

It is again pointed out that, inasmuch as the hinge of my invention isattached directly to the oven liner rather than to the stove frame orother parts which will not receive the full heat of the oven, therewiill be substantially no heat differential between the hinge mechanismand the oven and hence the difficulties of proper closure which Hence, Ido not wish to'be'lirnited to the specific embodiments shown anddescribed or uses mentioned, but intend the same to be merely exemplary,the scope of my invention'being limited only by the appended claims.

I claim:

1. The combination of a cabinet having a closure door and a hingemounting said door on the cabinet on a horizontal axis at the bottom ofthe door, said hinge comprising a pair of arms pivoted at spaced pointson the door, one of said arms being fixed to the cabinet, a cam pivotedat spaced points thereon to said arms, and a spring-biased leverpivotally carried by said one of said arms and acting on a surface ofsaid cam and'therethrough against the other arm at such point, and insuch direction on the operative surface of said cam as to counterbalancethe door, said cam surface being so arranged that the counterbalancingeifect of .said spring-biased lever will increase in the course ofopening movement of said door.

2. A combination as defined in claim 1 having an auxiliaryspringconnccted to the cam and the cabinet and normally ineffective whenthe door is closed and so arranged that it will becomeetl'ective as acounterbalancing force on the door only after the latter has beenpartially opened by a substantial amount.

3. A combination as defined in claim 2 wherein the auxiliary spring isattached at such a point on the cam that the spring will exertsubstantial tension-a1 force on the cam only after the latter has beenrotated. about 45 from its position when the door is closed.

4. A combination as defined in claim 3 wherein said cam has a relativelylong convex arcuate dwell and a relatively short concave dwell adjacentone end of the convex dwell, said spring biased lever having anantifriction member engaging the convex dwell during the opening of thedoor and engaging the concave dwell in i the closed position of thedoor, said concave dwell providing a relatively slight resistance to theopening of the door.

5. The combination of claim 1 wherein the cabinet is a cabinet oven,said oven having a sheet metal liner and said hinge being attached inheat-conductive relation to said liner.

6. A combination as defined in claim 1 wherein both of said arms have asubstantially straight portion and a portion offset therefrom in thesame direction, the olfset portions being attached to the door at pointsso' spaced that, when the door is fully open, thestraight portions willlie adjacent and substantially parallel to each other, whereby toprovide a stop to limit opening movement of the door.

7. A combination as defined in claim 6 wherein said cam has a relativelylong convex arcuate dwell and a relatively short concave dwell adjacentone end of the convex dwell, said spring biased lever having anantifriction member engaging the convex dwell during the opening of thedoor and engaging the concave dwell in the closed position of the door,said concave dwell providing a relatively slight resistance to theopening of the door.

8. A combination as defined in claim 1 having a bearing carried by saidlever and engaging a surface of said cam in counteraction to the gravityeffect on the door in open and partially open positions.

9. A combination as defined in claim 1 wherein the cam is attached tosaid one of said arms by means of a keyhole slot in one of the two lastmentioned members and a stud in the other of said members. I

10. A combination as defined in claim 1 wherein said cam has arelatively. long convex arcuate dwell and a relatively short concavedwell adjacent one end of the convex dwell, said spring biased leverhaving an antifriction member engaging the convex dwell during theopening of the door and engaging the concave dwell in the closedposition'of the door, said concave dwell providing a relatively slightresistance to the opening of the door- 11. A combination as defined inclaim 1 wherein said cam has a relativelylong convex arcuate dwelleccentric to the axis of rotation of said cam, whereby, as the door ismoved to maximum opening, the cam will disproportionately increase thecounterbalancing spring resistance through its reaction against saidspring biased lever.

12. A combination as defined in claim 1 wherein said cam has arelatively long convex arcuate dwell eccentric to the axis of rotationof said cam, whereby, as the door is moved to maximum opening, the camwill disproportionately increase the counterbalancing spring resistancethrough its reaction against said spring biased lever, and an auxiliaryspring connected to the cam and the cabinet and normally ineffectivewhen the door is closed and so arranged that it will become eifective asa counterbalancing force on the door only after the latter has beenpartially opened by 'a'substantial amount.

References Cited in the file of this patent UNITED STATES PATENTSDavidson Aug. 12, 1947

